Turns out latest upstream U-Boot does not configure/enable pllu which leaves it at some default rate of 500 kHz: root@apalis-t30:~# cat /sys/kernel/debug/clk/clk_summary | grep pll_u pll_u 3 3 0 500000 0 Of course this won't quite work leading to the following messages: [ 6.559593] usb 2-1: new full-speed USB device number 2 using tegra- ehci [ 11.759173] usb 2-1: device descriptor read/64, error -110 [ 27.119453] usb 2-1: device descriptor read/64, error -110 [ 27.389217] usb 2-1: new full-speed USB device number 3 using tegra- ehci [ 32.559454] usb 2-1: device descriptor read/64, error -110 [ 47.929777] usb 2-1: device descriptor read/64, error -110 [ 48.049658] usb usb2-port1: attempt power cycle [ 48.759475] usb 2-1: new full-speed USB device number 4 using tegra- ehci [ 59.349457] usb 2-1: device not accepting address 4, error -110 [ 59.509449] usb 2-1: new full-speed USB device number 5 using tegra- ehci [ 70.069457] usb 2-1: device not accepting address 5, error -110 [ 70.079721] usb usb2-port1: unable to enumerate USB device Fix this by actually allowing the rate also being set from within the Linux kernel. Signed-off-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx> --- drivers/clk/tegra/clk-pll.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c index 7c369e21c91c..830d1c87fa7c 100644 --- a/drivers/clk/tegra/clk-pll.c +++ b/drivers/clk/tegra/clk-pll.c @@ -1151,6 +1151,8 @@ static const struct clk_ops tegra_clk_pllu_ops = { .enable = clk_pllu_enable, .disable = clk_pll_disable, .recalc_rate = clk_pll_recalc_rate, + .round_rate = clk_pll_round_rate, + .set_rate = clk_pll_set_rate, }; static int _pll_fixed_mdiv(struct tegra_clk_pll_params *pll_params, -- 2.14.3 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html